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We
thank Dr. Gerard Abadjian, Hotel-Dieu de France, Beirut, Lebanon for contributing this case.We
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Case of the Week #23

An 80
year old man was admitted for open biopsy of a lung nodule.Nine months previous, the patient noticed
edema of the face and neck region, which disappeared two months later.Since that time, he had a generalized
pruritis and a weight loss of 6 kg, but no other symptoms.

A
workup disclosed a positive PPD, multiple, diffusely enlarged mediastinal lymph
nodes and a venous thrombosis extending to the left jugular vein.

Epithelioid
angiosarcoma is characterized by sheets of tumor cells with vascular spaces
lined by polygonal or oval cells with abundant eosinophilic cytoplasm and
large, atypical nucleiVasoformative areas (irregular sinusoidal vascular channels) are
less common than in classic angiosarcomas.There often is intra-arterial or lymphagitic spread (Archives
2005;129:e7).The tumor is accompanied by
hemorrhage, necrosis and mitotic figures.Focal hemangioendothelioma-like areas with intracytoplasmic lumina may
be present.Tumor cells typically are
immunoreactive for endothelial cell markers such as CD31, CD34 and Factor VIII
related antigen, although all vascular markers may not be immunoreactive.They are also immunoreactive for vimentin,
and often express cytokeratins.

Primary
epithelioid angiosarcomas of the lung are unusual, with less than 20 cases
reported, and the differential diagnosis includes the much more common
metastatic tumor (Arch
Bronconeumol 2004;40:188).Metastatic angiosarcomas
typically present with dyspnea, chest pain or hemoptysis, with multiple lung
nodules identified radiologically.Among
all angiosarcomas metastatic to the lung, the primary is only identified at
presentation half of the time (Mod
Path 2001;14:1216), often in skin,
soft tissue or the right atrium.

The
differential diagnosis also includes epithelioid hemangioendothelioma, a low
grade sarcoma that typically affects middle aged women.These tumors tend to be acellular centrally,
and more cellular at the periphery.The
tumor cells have eosinophilic and often vacuolated cytoplasm, with bland or only
mildly atypical nuclei.The stroma may
have myxochondroid features.Hemorrhage,
necrosis and mitotic figures are not prominent.Melanoma and carcinoma may be differentiated based on immunostains, with
the caveat that epithelioid angiosarcomas are often cytokeratin positive.